The auto industry and other industries having production assembly lines have developed a concept of checking, which includes the making of a master cube comprising a plurality of the individual panels of an automobile and the like, which may be quickly and easily used at an inspection gage or a check station to insure that the actual panels being assembled are dimensionally correct. Heretofore, in order to make the various checking gage models that comprise the master cube of an autombile, or the like, they were built by first building a wood model of the inner surface and then taking a female mold therefrom, and then laying up inside the female to get an outside shell, and then making a wood model of the inner surface and taking a female mold therefrom, and then getting an outside shell therefrom, and then putting the two shells together. A disadvantage of the aforedescribed prior art method of making a checking gage model is that it is time consuming, and expensive. A checking gage wood model formed in accordance with said prior art method is not stable due to the element of moisture, heat, cold and so forth.